Three minutes to understand the gearbox

Three minutes to understand the gearbox

1. What is a gearbox?

The gearbox is a mechanical device used to change the engine speed and torque. It can change the transmission ratio of the output shaft and the input shaft by fixing or stepping, which is also called gearbox. The gearbox is composed of variable speed transmission mechanism and control mechanism, and some cars also have power output mechanism. Most of the transmission mechanisms are ordinary gear transmission, and some are planetary gear transmission. The common gear transmission mechanism generally adopts sliding gear and synchronizer.

Second, the classification and characteristics of gearbox

Gearboxes are divided into manual gearboxes and automatic gearboxes, among which automatic gearboxes are divided into ordinary automatic gearboxes, manual-automatic integrated gearboxes, stepless gearboxes and dual-clutch gearboxes.

1, manual transmission (MT), commonly known as manual gear.

This is the most traditional and oldest gearbox with simple structure, low manufacturing and maintenance costs, high transmission efficiency and high reliability. Advantages are mainly reflected in the driving experience, you can master the timing of shifting by yourself, and you have a good performance in power and fuel saving.

However, the operation is complicated, and it is not easy for novice drivers to frequently step on the clutch to shift gears when driving on congested urban roads.

2. Automatic transmission (AT), commonly known as automatic transmission.

AT is the originator of the automatic transmission camp, and it is also the most mature and widely used automatic transmission at present. It saves the trouble of stepping on the clutch, does not need to shift gears back and forth, is simple to operate and easy to drive, and is suitable for driving in crowded cities. But for ordinary automatic transmission, it is impossible to completely eliminate the sense of frustration when shifting gears, and there is no driving pleasure. Compared with the manual transmission model, the fuel consumption will be higher.

3. Automatic clutch gearbox (AMT)

AMT is based on the original mechanical gearbox (manual gear), which mainly changes the manual shift control part. That is to say, under the condition that the overall transmission structure is unchanged, the automation of gear shifting is realized by adding an automatic control system controlled by a microcomputer. It maintains the basic structure of the original mechanical transmission, and has the advantages of high transmission efficiency, compact structure, low cost, easy manufacture, reliable work and convenient operation. However, during the driving process of AMT, shifting brings strong frustration and poor comfort, and power interruption may occur during shifting. As a product of compromise between MT and AT, AMT is not the mainstream of the market.

4. Continuously variable transmission

CVT is a gearbox without fixed gears, which can be said to be the most ideal automobile transmission. The transmission ratio can be adjusted linearly to realize stepless speed change, which makes the vehicle very stable in the acceleration process and has no sense of frustration when shifting gears in the traditional automatic gearbox. In terms of fuel consumption performance, CVT is also superior to ordinary automatic transmission.

The CVT continuously variable gearbox is driven by two conical disks and steel belts, which is easy to slip, not suitable for heavy-load and rapid acceleration operation, and cannot match the high-horsepower engine. Moreover, because the structure and technology are more complex and advanced, its maintenance cost is higher than that of ordinary automatic gearbox. CVT gearbox car is suitable for home use, which is worthy of recognition.

5. Dual clutch gearbox (DCT/DSG)

Dual clutch gearbox is a new gearbox with subversive design, which not only inherits the characteristics of high transmission efficiency of manual gearbox, but also shifts gears faster than manual gearbox, and is the most advanced gearbox at present. It has the advantages of smooth shifting, no sense of frustration in general gearbox shifting, high efficiency, fuel saving and high comfort.

However, compared with other gearboxes, the dual clutch gearbox has complex structure, high cost, high maintenance cost and low reliability. In particular, dry power shifting is easy to overheat protection when the domestic congested roads are in a semi-linkage state because there is no oil cooling.

Compare various gearboxes as a whole:

Performance: DSG>；; MT & gtAT & gt amount & gtCVT

Comfort: CVT & gtDSG & gt；; AT> amount & gtMT；;

Economically: MT & gtCVT & gtDSG & gt；; AT & gtAMT

Driving pleasure: MT & gtDSG & gt；; AT> amount & gtCVT

Maintenance: MT & gtAT & gt amount & gtCVT & gtDSG.

Each gearbox has its own advantages and disadvantages. You can choose the gearbox that suits you according to your own economic conditions, driving habits and other aspects.